Some Scots wi' glasses drink (4)
I believe the answer is:
swig
'drink' is the definition.
(I know that swig is a type of drink)
'some scots wi' glasses' is the wordplay.
'some' says the answer is hidden in the clue (some parts of the word are used).
'SWIG' is hidden in the letters of 'scots wi glasses'.
(Other definitions for swig that I've seen before include "Slug" , "(Take) quick drink from bottle" , "Swallow (drink) greedily" , "Large draught of drink" , "Drink in large draughts" .)